Finding the Fourth Proportional to 139,222.99, 208,784.67 and 54,979.75

Step by Step Solution

1. Step 1: Write the proportion equation
   139,222.99 : 208,784.67 = 54,979.75 : x
2. Step 2: Convert to fraction form
   139,222.99/208,784.67 = 54,979.75/x
3. Step 3: Cross multiply
   139,222.99x = 208,784.67 × 54,979.75
4. Step 4: Simplify right side
   139,222.99x = 11,478,928,960.43
5. Step 5: Solve for x
   x = 11,478,928,960.43/139,222.99
6. Step 6: Final answer
   x = 82,449.95